180 THE FIRST BOOK OF BOTANY. 



EXEECISE LXVIII. 

 Sutures and Dehiscence. 



LOOK among the ripe and dry pea and bean pods, 

 upon the dry vines, for those that have begun to open. 

 Examine the edges of the separate parts. Do you 

 see something like a joint where the two parts were 

 united ? Compare them with Fig. 291. 



FIG. 291. 



DEIIIS'CENCE. The opening of a seed-vessel at 

 maturity. See Fig. 291. 



STJT'TJKE. A seam. The line along which dehis- 

 cence occurs, and so permits the escape of the seeds. 



VEN'TRAL SUTURE. The inner suture of a carpel. 

 The one looking toward the centre of the flower. In 

 Fig. 291, it is the suture along which the ovules are 

 attached. 



DOR'SAL SUTURE. The outer suture. See Fig. 291. 



What name is given to those joints in ovaries at 

 which they open when the seeds are ripe ? How many 



